10 Gbit/s, 300 km repeaterless transmission with SBS suppression by the use of the RZ format

Abstract
The authors have confirmed experimentally that employing the RZ format instead of the NRZ format increases the SBS threshold by ~3 dB. By using the RZ format, we have successfully conducted 10 Gbit/s repeaterless transmission through 300 km of DSF. This is the longest repeaterless transmission at 10 Gbit/s ever reported.